Gazebo ROS2 bridge

#bridge   #ros2   #gazebo   #gz   #ros_gz_bridge  

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Table of Content

Gazebo ROS2 bridge

This package provides a network bridge which enables the exchange of messages between ROS2 and Gazebo Transport. more

ros2 run ros_gz_bridge parameter_bridge <topic name>@<ros msg type>@<gazebo msg type>

---

Simple demo

Send gazebo clock topic to ROS2 from gazebo (garden) empty world

• Run bridge from CLI
• Run bridge from launch file
• Run bridge from launch with yaml config

gz topics

gz topic --list
#
/clock
/gazebo/resource_paths
/gui/camera/pose
/stats
...

From CLI

run bridge from cli

ros2 run ros_gz_bridge parameter_bridge "/clock@rosgraph_msgs/msg/Clock[gz.msgs.Clock"

Closing the rule in quotation marks

In zsh without the quotation we get zsh: bad pattern: error

message direction

Direction
@	Bridge both directions
[	GZ->ROS Bridge
]	ROS->GZ Bridge

ros2 topics

ros2 topic list
#
/clock
/parameter_events
/rosout

echo topic

ros2 topic echo /clock
#
clock:
  sec: 2832
  nanosec: 447000000
---
clock:
  sec: 2832
  nanosec: 448000000

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Using launch file

bridge.launch.py

import launch
from launch_ros.actions import Node


def generate_launch_description():
    ld = launch.LaunchDescription()
    bridge = Node(
        package="ros_gz_bridge",
        executable="parameter_bridge",
        arguments=[
            '/clock@rosgraph_msgs/msg/Clock[gz.msgs.Clock'
        ],
        output="screen",
    )

    ld.add_action(bridge)
    return ld

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Using launch with yaml file

Using yaml to config bridge mapping

direction
BIDIRECTIONAL	Default “BIDIRECTIONAL” - Bridge both directions
GZ_TO_ROS	Bridge Ignition topic to ROS
ROS_TO_GZ	Bridge ROS topic to Ignition

more yaml config option

bridge.yaml

- ros_topic_name: "/clock"
  gz_topic_name: "/clock"
  ros_type_name: "rosgraph_msgs/msg/Clock"
  gz_type_name: "gz.msgs.Clock"
  direction: GZ_TO_ROS

bridge.launch.py

import pathlib
import launch
from ament_index_python.packages import get_package_share_directory
from launch_ros.actions import Node


def generate_launch_description():
    ld = launch.LaunchDescription()
    pkg_project_bringup = get_package_share_directory("nav_bringup")
    bridge_config = pathlib.Path(pkg_project_bringup).joinpath("config", "gz_bridge.yaml").as_posix()
    bridge = Node(
        package="ros_gz_bridge",
        executable="parameter_bridge",
        parameters=[
            {
                "config_file": bridge_config
            }
        ],
        output="screen",
    )

    ld.add_action(bridge)
    return ld

Using ExecuteProcess

Run bridge with yaml config using ExecuteProcee action

import pathlib
import launch
from ament_index_python.packages import get_package_share_directory
from launch.actions import ExecuteProcess


def generate_launch_description():
    ld = launch.LaunchDescription()
    pkg_project_bringup = get_package_share_directory("nav_bringup")
    bridge_config = pathlib.Path(pkg_project_bringup).joinpath("config", "gz_bridge.yaml").as_posix()
    bridge = ExecuteProcess(
        cmd=[
            'ros2 run ros_gz_bridge parameter_bridge  --ros-args -p config_file:={}'.format(bridge_config)
            ],
        output='screen',
        shell=True
    )

    ld.add_action(bridge)
    return ld